Hello Roland !
In my copy of Eugene Bender's book, "Luger holsters & Accessories Of The 20th. Century" on page 495, Mr. Bender states "...tubes (of the cleaning kits) were made of brass until the advent of World War I, after which there were fabricated of sheet metal.".
After 1949, they were of sheet metal but of a little different configuration...the photo of the 1949 kit Mr. Bender shows has all the cleaning parts of brass and the container of sheet metal only.
I own one kit from 1882 and two kits from 1900; all have brass tubes and all misc. parts are of brass construction, except the longer main shaft with has the screw-driver end...that is made of carbon steel.
Hope this info. helps...
Regards,
Pete... <img border="0" alt="[typing]" title="" src="graemlins/yltype.gif" />